US2689734A

US2689734A - Phonograph

Info

Publication number: US2689734A
Application number: US223306A
Authority: US
Inventors: Wennerbo Erik; Svensson Fritz August
Original assignee: Industriaktiebolaget Luxor
Current assignee: Industriaktiebolaget Luxor
Priority date: 1950-05-08
Filing date: 1951-04-27
Publication date: 1954-09-21
Anticipated expiration: 1971-09-21
Also published as: CH291250A

Description

P 21, 1954 E. WENNERBO ETAL 2,689,734

PHONOGRAPH Filed April 2'7, 1951 2 Sheets-Sheet 1 FIG.

p 21, 1954 E. WENNERBO ETAL 2,689,734

PHONOGRAPH Filed April 27, 1951 2 Sheets-Sheet 2 FIG. 2

INVENTORS El-ck We finer-5o F 'L ZZ A, Jvensson BY W A ORNEW Patented Sept. 21, 1954 2,689,734 PHONOGRAPH Erik, Wennerbo, Motala, and Fritz August Svensscn, Halmstad, Sweden, assignors to Industriaktiebolaget Luxor, Mote-la, Sweden, a; Swedish joint-stock company Application, April 27, 1951, Serial Nbz- 223306 Claims priority, application Sweden May 8, I950 3 Claims. 1

The present invention. relates to phonographs of the type provided with means for changing the rotational speed of the record carrying member (turntable) between a higher value (78 R. P. M.) for the playing or the hitherto usual records and at least one lower value (33 and 45 R. P. M.) for the playing of so-calledlong-playing records (LP records).

LP records require for their playing a needle or stylus whose shape is different from that of the hitherto usualstylus, and therefore it is necessary in phonographs for playing both, kinds of records to use two different needles. The present invention provides for a simple and reliable means. in such phonographs for automatically bringing the cl'rect needle into workin position when therotational speed of the record carrying member is changed.

In the phonograph according toour invention a sleeve is rotatably mounted in the pick-upcasing, a pin being yieldingly connected to said sleeve at its one end and carrying at its other end two phonograph needles projecting substantially radially therefrom and at an angle relatively to each other, of which needles one is a needle for playing standard records and the other is a needle for playing LP records, amechanical connection permitting rotational movement of said needlecarrying pin being provided between the pin and the transducer unit of the pick-up for transmitting the needle vibrations to the latter unit, the speed changing means being connected to a mov able member which is adapted to rotate the'sleeve together with the pin and the phonograph needlesupon actuation of said speed changing means so as automatically to move the correct phonograph needle into the workingpositi-on.

For the explanation of the invention reference is had to the accompanying drawings which show a preferred embodiment of the invention.

In Fig. 1 of the drawings, l designates a pickup casing. In the under side of this casing there is a rectangular recess 2 in the opposite end walls of which the two ends 3 and of a sleeve-5 are rotatably mounted. The right hand end 4 of the sleeve engages a bore 9 in the casing l and contains a helical spring 1 and a ball 8 which is forced against the bottom of the bore 9 by said spring, and. the left hand end 3 of the. sleeve is inserted from below into a groove l0 formed in the casing I and is forced by the spring I axially against an abutment in said groove so that the sleeve 5 will be retained in the pick-up casing in the position shown. The sleeve 5 may readily be removed from the casing I by being displaced 2. to the right against the action of the spring T whereupon the left hand end 3 is moved out of the groove Hi and finally the right hand end 4 is pulled out of the bore: 9;

Into the left hand end of the sleeve 5 arubber stopper tl is. inserted. This stopper carries a pin i i substantially coinciding with the axis of the sleeve and? carrying at its free end: two radially extending needles 13. and M, respectively, which form right angles with each other.

The pin t2 engages a fork-shaped end of a second pin [5 which isconnected to a transducer unit it for converting mechanical vibrations into electrical impulses and comprising a piezo-electrical crystal, for instance; The vibrations of the needle [3 (or M")- are thus transmitted to the transducer unit through the pins 12 and IS.

The middle portion 5 of the sleeve 5 is can tenedand twisted a quarter of a revolution, as shown. The twisted or helical portion 6 is adapted to cooperate with the fork-shaped end of an arm H which, in turn, is coupled to a control device for changing the rotational speed of the record carrying member and which is moved longitudinally relatively to the sleeve 5 when the said control device is actuated, thereby rotating the sleeve 5 through a quarter of a revolution between its two end positions. If the needle 5 3 which is shown in the working position in the drawing is a needle for playing standard records (recorded at a speed of 7-8 R. P. M.) and the needle M is one for playing LP records, changing the rotational speed from 78 R; P. M. to 33 or R. Pi M will? cause the arm I? to be moved to the. left whereby the sleeve 5 will be rotated anti-clockwise (as viewed from the left hand end 3* of the sleeve) and the needle id for LP records will be moved down into the working position.

Figure 2 shows the entire arm [1, one end of which is fork-shaped for engaging the helical portion 6 whereas the other end of the arm forms a handle 18. The arm I! has a cam surface I!) engaging a pin 26 which is carried by an arm 22 on the phonograph motor 2!. The motor 2| has a shaft 23 which in the position shown in the figure engages an intermediate wheel 24 which, in turn, engages an inner flange 26 on the turntable, said flange being concentric with the turntable shaft 27. The turntable has also an outer concentric flange 28. In the position of the various details shown in the figure the motor shaft 23 rotates the intermediate wheel 24 which engages the flange 25 and rotates the turntable at a speed of '78 R. P. M. If the arm I! is displaced upwards in the direction of the arrow the pin 20 actuates 3 the cam surface I9 and moves the arm 22 and the motor 2| to the left so that the motor shaft 23 engages the outer flange 28 and thus rotates the turntable at a speed of 33 /3 R. P. M.

Modifications of the device as described above are conceivable within the scope of the appended claims.

ing substantially radially therefrom and at an angle relatively to each other, one of said needles being a needle for playing standard records and the other being a needle for playing LP records, a transducer unit mounted in the pick-up casing, a mechanical connection permitting relative rotational movement provided between said needle-carrying pin and said transducer unit for transmitting the needle vibrations to the latter, a substantially linearly movable member connected to said speed changing means and adapted to cooperate with the helical guide means of the sleeve for automatically rotating said sleeve upon actuation of the speed changing means for moving the correct needle into the working position, the sleeve being rotatably mounted in the pick-up casing at its ends, an intermediate portion of the sleeve being flattened and twisted helically, and said helical portion being adapted to cooperate with the fork-shaped end of an arm which is connected to the speed changing means and is adapted to be moved thereby in the longitudinal direction of the sleeve upon actuation of said speed changing means for changin the rotational speed of the record carrying member.

2. In a phonograph provided with means for changing the rotational speed of the record carrying member between a higher value for the playing of standard records and at least one lower value for the playing of LP records, a tone arm, a transducer casing in said tone arm, said casing being kept against rotation around the length axis of the tone arm, a sleeve rotatably mounted in said casing, a pin yieldingly connected to said sleeve at its one end and carrying at its other end two phonograph needles projecting substantially radially therefrom and at an angle relatively to each other, of which needles one is a needle for playing standard records and the other is a needle for playing LP records, a transducer unit mounted in the transducer casing, a coupling member secured to said transducer, a recess in the free end of said coupling member, an integral portion of said pin rotatably engaging said recess and mechanical means connecting said sleeve with said speed changing means for automatically rotating said needle-carrying pin upon actuation of the speed changing means so as to move the correct needle into the working position.

3. In a phonograph provided with means for changing the rotational speed of the record carrying member between a higher value for the playing of standard records and at least one lower value for the playing of LP records, a tone arm, a transducer casing in said tone arm, said casing being kept against rotation around the length axis of the tone arm, a sleeve rotatably mounted in said casing said sleeve having an intermediate portion flattened and twisted helically, a pin yieldingly connected to said sleeve at its one end and carrying at its other end two phonograph needles projecting substantially radially therefrom and at an angle relatively to each other, of which needles one is a needle for playing standard records and the other is a needle for playing LP records, a transducer unit mounted in the transducer casing, a couplin member secured to said transducer, a recess in the free end of said coupling member, an integral portion of said pin rotatably engaging said recess and mechanical means connecting said sleeve with said speed changing means, said means comprising a substantially linearly movable member having a forkshaped end cooperating with said helical portion of the sleeve and adapted to be moved in the longitudinal direction of the sleeve for automatically rotating said sleeve for bringin the correct needle into the working position upon actuation of said speed changing means for changing the rotational speed of the record carryin member.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,127,873 Dyer Feb. 9, 1915 1,389,885 Lewis Sept. 6, 1921 1,843,845 Stunz Feb. 2, 1932 1,992,893 Thomas Feb. 26, 1935 2,067,347 Rysick Jan. 12, 1937 2,113,401 Goldsmith Apr. 5, 1938 2,526,188 Andres Oct. 17, 1950 2,532,803 Faus Dec. 5, 1950 2,568,671 Vistain Sept. 18, 1951 2,572,712 Fisher Oct. 23, 1951 2,601,126 Palo June 17, 1952